Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

097
FXUS63 KLOT 110530
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1230 AM CDT Mon May 11 2026

.KEY MESSAGES...

- Briefly warmer (70s) and windy on Tuesday with the potential
  for showers and storms.

- Otherwise cooler (60s) and dry conditions are favored through
  Thursday before a warm-up commences heading into the weekend
  with additional shower/storm chances.

&&

.DISCUSSION...
Issued at 247 PM CDT Sun May 10 2026

Cooler conditions prevail for Mother`s Day today with
temperatures in the 50s near the lakeshore and lower to mid 60s
inland. A convergence axis has set up on the western side of
Chicago extending well into northwest Indiana where the drier
northwest flow meets the lake modified airmass and associated
northeast to east winds. This stalled lake breeze boundary will
eventually progress a bit farther inland later this afternoon
into early evening.

Cloud cover associated with an axis of mid-level moisture
sagging south across the area through this evening and
overnight may slow our cooling initially before clouds clear out
toward daybreak. Given the cooler regional airmass in place,
still anticipate temperatures will fall into the upper 30s
across interior northern Illinois late tonight (40s expected
elsewhere). Meanwhile a surface trough axis/lake enhanced
boundary will dive south across the area late tonight into early
Monday morning. Increased low-level flow in the wake of this
feature may produce sufficient mixing of the near surface layer
to limit frost coverage in those areas, so have opted to hold
off on a Frost Advisory and maintain "patchy" wording near the
WI/IL state line with this update.

Cooler temperatures will continue into Monday as the center of
high pressure sets up to our north leading to continued onshore
flow from Lake Michigan (50s near the lake and 60s farther
inland). A reinforcing lake breeze will then progress well
inland late in the afternoon through the evening followed by
temperatures falling steadily in its wake.

We continue to monitor the potential for showers and storms on
Tuesday associated with a trough expected to dive across the
region. Warm and moist advection ahead of this feature will
allow temperatures to warm well into the 70s across the area
paired with strong southwesterly winds gusting up to 35-40+ mph
during the afternoon. A north to south oriented axis of warm
advective showers may try to brush northern Illinois early
in the morning on Tuesday ahead of the main system and
associated cold front. Additional showers and storms may then
develop along the front and move across the area into the
afternoon and evening. Marginal mid-level lapse rates and low-
level moisture will limit the overall strong to severe potential
here locally but will have to monitor model trends closely
given strong deep layer shear in place. Will have to keep an
eye out for the potential for locally stronger storms given
sufficient shear in place in spite of marginal mid-level lapse
rates and instability. The strong southwesterly winds may also
lead to some blowing dust concerns, especially in rural and open
areas near recently worked over farm fields.

Temperatures briefly cool down once more in the wake of
Tuesday`s cold front, with high temperatures on Wednesday back
in the 60s. We then gradually warm up each day through the end
of the week as upper level ridging builds across the central
CONUS into the Upper Midwest by the weekend. The degree of
warmth remains somewhat in question given the potential for a
closed mid-level low feature moderating things a bit. Blended
guidance has accordingly trended a bit cooler with the latest
update, with forecast highs in the mid 70s to lower 80s over
the weekend.

Petr

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 1230 AM CDT Mon May 11 2026

VFR conditions with passing mid to upper-level clouds will
persist through the period. A low pressure trough moving
southward near the IL/WI line at TAF issuance will shift winds
NNE/NE 10 to 15 knots early this morning. Some sporadic gusts to
20 knots are possible after daybreak, but winds should
generally remain 10 to 15 knots through the day. Expect ENE/E
winds under 10 knots this evening to gradually increase to
around 10 knots while veering S by sunrise Tuesday.

Kluber

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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